Credit: The Associated Press

FILE - This June 20, 1990 file photo shows Winnie Mandela pointing out something in the crowd to her husband Nelson Mandela, during a welcoming ceremony at New York's City Hall as they kicked of a three-day stay in the city. The FBI investigated multiple death threats against Nelson Mandela during his 1990 visit to the United States and relied on an informant for details about the anti-apartheid leader’s trip, according to newly released documents. The FBI released hundreds of pages of records tied to Mandela’s visit, which came months after was released from a 27-year prison sentence in South Africa and four years before he became president. (AP Photo/David Longstreath, File)

WASHINGTON — The FBI investigated multiple death threats against Nelson Mandela during his 1990 visit to the United States and relied on an informant for details about the anti-apartheid leader's trip, according to newly released documents.

The FBI released hundreds of pages of records tied to Mandela's visit, which came months after he was released from a 27-year prison sentence in South Africa and four years before he became president.